A chassis of an automobile normally consists of a central body, forming the passenger compartment, and a front body supporting the front wheels and a rear body supporting the rear wheels. The engine may be arranged in frontal position, and thus accommodated in the front body, or in central or rear position, and thus accommodated in the rear body.
At the passenger compartment and approximately in the middle of the automobile, the chassis comprises two central pillars, each of which rises vertically from a door sill and ends at the roof. In most automobiles on the market, each side (e.g., comprising the door sill and the central pillar) is made of several pressed parts, which are superimposed and welded. Such a constructive method is fast and cost-effective when the material used for the chassis is steel and/or when a high number of parts are made (i.e. for mass manufactured automobiles), while it is more complex and costly when the material used for the chassis is aluminum and/or when a low number of parts are made (i.e. for small series automobiles).
Patent application EP1498345A2 describes a vehicle provided with a pair of door sills arranged longitudinally underneath the zone of the doors, and each having a through hole; and a pair of central pillars, each of which raises perpendicularly and vertically from a door sill, is made in one piece, is inserted in an interlocking way in the through hole of a window sill, and is welded to the window sill at the through hole.